package com.xtwy.interceptor;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;
import org.springframework.stereotype.Service;

import javax.servlet.*;
import java.io.IOException;

/**
 * @作 者: 侯建军
 * @日 期: 2018/7/29 12:35
 * @描 述: 一个自定义的filter，
 *     必须包含authenticationManager,accessDecisionManager,securityMetadataSource三个属性，
 *     我们的所有控制将在这三个类中实现
 * @公 司：山西迅腾伟业
 */
@Service
public class AuthFilterSecurityInterceptor extends AbstractSecurityInterceptor implements Filter {
    /**
     * 注入资源数据定义器
     */
    @Autowired
    private FilterInvocationSecurityMetadataSource securityMetadataSource;

    /**
     * 注入访问决策器
     * @param myAccessDecisionManager
     */
    @Autowired
    public void setMyAccessDecisionManager(MyAccessDecisionManager myAccessDecisionManager) {
        super.setAccessDecisionManager(myAccessDecisionManager);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    /**
     * 过滤器方法
     * @param request
     * @param response
     * @param chain
     * @throws IOException
     * @throws ServletException
     */
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        FilterInvocation fi = new FilterInvocation(request, response, chain);
        invoke(fi);
    }

    public void invoke(FilterInvocation fi) throws IOException, ServletException {
        //fi里面有一个被拦截的url
        //里面调用InvocationSecurityMetadataSource的getAttributes(Object object)
        // 这个方法获取fi对应的所有权限
        //再调用AuthAccessDecisionManager的decide方法来校验用户的权限是否足够
        InterceptorStatusToken token = super.beforeInvocation(fi);
        try {
        //执行下一个拦截器
            fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
        } finally {
            super.afterInvocation(token, null);
        }
    }
    @Override
    public void destroy() {

    }
    @Override
    public Class<?> getSecureObjectClass() {
        return FilterInvocation.class;
    }
    @Override
    public SecurityMetadataSource obtainSecurityMetadataSource() {
        return this.securityMetadataSource;
    }
}
